One type of prior art metal-oxide-semiconductor ("MOS") electrically programmable read-only memory ("EPROM") uses memory cells that have electrically isolated (i.e., floating) gates. Information is stored in the memory cells in the form of electrical charge on the floating gates.
One prior EPROM is the flash erasable and electrically programmable read-only memory ("flash EPROM"). The flash EPROM can be programmed by a user, and once programmed, the flash EPROM retains its data until erased. Once programmed, the contents of the flash EPROM can be erased by electrical erasure. The flash EPROM may then be reprogrammed with new code or data.
Prior art personal computer systems typically employ removable data storage media. One common prior art removable storage medium is a floppy disk. A relatively new prior art storage medium is an integrated circuit-based memory card ("IC memory card").
Prior art flash EPROMs are nonvolatile and reprogrammable, and this has permitted the flash EPROM technology to be used for removable data storage. One such prior art application is the flash EPROM memory card ("flash memory card"). The flash memory card typically includes a number of flash EPROMs. The flash memory card can be erased and programmed electrically.
One disadvantage of this prior art flash memory card is that the card typically requires a program/erase power supply voltage V.sub.PP of 12 volts for programming and erasure of the flash EPROMs in the card in addition to the device power supply V.sub.CC of 5 volts to the card.
Prior art personal computer systems, however, typically do not provide dual power supply voltages for their external memory cards. When a flash memory card is inserted into a computer system that only includes the device power supply voltage V.sub.CC, the flash memory card is unable to be reprogrammed and can only serve as a read-only memory card.
In addition, because small size is important, prior art laptop and notebook computers typically have minimal space for electrical circuitry, including voltage generation circuitry. Furthermore, weight is typically kept to a minimum for prior art laptop and notebook computers.